Rubber composition that can be used for manufacturing a tyre of which the composition comprises a starch and an aqueous or water-soluble plasticizer

Abstract

A rubber composition based on a diene elastomer, a crosslinking system, and a reinforcing filler is provided, as well as a process for obtaining the composition. The composition includes a starch in a proportion of from 10 to 50 phr (parts by weight per hundred parts of elastomer) and an aqueous or water-soluble plasticizer in a proportion of from 3 to 30 phr. The aqueous or water-soluble plasticizer is water or a mixture of water and glycerol, in which the water is predominant by weight in the aqueous or water-soluble plasticizer. The composition can be used for preparing calendered or profiled tyre-related products, such as a tyre tread, for example.

1 - 19 . (canceled) 
     
     
         20 . A rubber composition comprising:
 a diene elastomer;   a crosslinking system;   a reinforcing filler;   a starch in a proportion of from 10 to 50 phr (parts by weight per hundred parts of elastomer); and   an aqueous or water-soluble plasticizer in a proportion of from 3 to 30 phr,   wherein the aqueous or water-soluble plasticizer is water or a mixture of water and glycerol, in which the water in the mixture is predominant by weight in the aqueous or water-soluble plasticizer.   
     
     
         21 . The rubber composition according to  claim 20 , wherein the proportion of the starch ranges from 15 to 40 phr. 
     
     
         22 . The rubber composition according to  claim 20 , wherein the proportion of the aqueous or water-soluble plasticizer ranges from 7 to 28 phr. 
     
     
         23 . The rubber composition according to  claim 20 , wherein the starch includes a minimum of 10% of amylose. 
     
     
         24 . The rubber composition according to  claim 23 , wherein the starch includes a minimum of 15% of amylose. 
     
     
         25 . The rubber composition according to  claim 24 , wherein the starch includes a minimum of 20% of amylose. 
     
     
         26 . The rubber composition according to  claim 20 , wherein the aqueous or water-soluble plasticizer is water. 
     
     
         27 . The rubber composition according to  claim 20 , wherein reinforcing filler includes predominantly carbon black. 
     
     
         28 . The rubber composition according to  claim 20 , wherein the reinforcing filler includes predominantly silica. 
     
     
         29 . The rubber composition according to  claim 20 , wherein the reinforcing filler includes a blend of carbon black and silica. 
     
     
         30 . The rubber composition according to  claim 20 , wherein the rubber composition is in a non-crosslinked state. 
     
     
         31 . The rubber composition according to  claim 20 , wherein the rubber composition is in a crosslinked state. 
     
     
         32 . The rubber composition according to  claim 20 , wherein the rubber composition is formed into a calendered or profiled product used in manufacturing a tyre. 
     
     
         33 . The rubber composition according to  claim 20 , wherein the rubber composition is formed into a tyre. 
     
     
         34 . A process for obtaining a rubber composition, the process comprising steps of:
 thermomechanical kneading of constituents of a composition, the constituents excluding a vulcanization system; and   adding to the composition, during the thermomechanical kneading step, a starch in a proportion of from 10 to 50 phr and an aqueous or water-soluble plasticizer in a proportion of from 3 to 30 phr, to obtain a rubber composition,   wherein the aqueous or water-soluble plasticizer is water or a mixture of water and glycerol, in which the water in the mixture is predominant by weight in the aqueous or water-soluble plasticizer, and   wherein the thermomechanical kneading step and the adding step are part of a first kneading phase.   
     
     
         35 . The process according to  claim 34 , wherein the proportion of the starch in the composition ranges from 15 to 40 phr. 
     
     
         36 . The process according to  claim 34 , wherein the proportion of the aqueous or water-soluble plasticizer in the composition ranges from 7 to 28 phr. 
     
     
         37 . The process according to  claim 34 , wherein the first kneading phase includes:
 kneading all elastomers of the composition;   subsequently adding the starch and the aqueous or water-soluble plasticizer in one portion or in parts; and   adding other constituents of the rubber composition after the starch and the aqueous or water-soluble plasticizer are added.   
     
     
         38 . The process according to  claim 34 , wherein the first kneading phase is carried out at a temperature of between 25° C. and 180° C.